TheMicrosporum gypseumcomplex (Nannizzia incurvataStockd.,N. gypsea(Nann.) comb. nov.,N. fulvasp. nov.)

Abstract

Isolates previously identified as Microsporum gypseum (Bodin) Guiart & Grigorakis have been found to be the imperfect states ofNannizzia incurvata Stockdale, N. gypsea (Nannizzi) comb. nov. and W.fulva sp. nov. The three species are heterothallic and cross-mating does not occur between them. They show slight but constant differences in their colonial and microscopic appearance on agar media and in the form of the peridial hyphae and appendages of their cleistothecia.Although the Microsporum states of N. incurvata and N. gypsea can be distinguished from each other it has been impossible to decide which, if either, of these is M. gypseum, sensu stricto. The imperfect state of N. fulva is M. fulvum Uriburu which had previously been considered synonymous with M. gypseum.In a previous report describing Nannizzia incurvata as a perfect state of Microsporum gypseum (Bodin) Guiart & Grigorakis (Stockdale, 1961) certain differences were noted between N. incurvata and Gymnoascus gypseus, described as the perfect state ofM. gypseum by Nannizzi (1927). It was also found that five of 12 isolates identified as M. gypseum failed to form cleistothecia alone or when mated with single ascospore isolates of N. incurvata.Other reports of the rediscovery of the perfect state of M. gypseum have been made: Griffin (1960) isolated a fungus which he considered to be conspecific with G. gypseus Nannizzi, although he found some differences and gave an amended diagnosis; and Szathm~ry & Herpay (1960) described the cleistothecia of M. gypseum and those of a closely related fungus, "Epidermophyton radiosulcatum var. flavum" Szathm~ry. The cleistothecia described by Szathm~ry & Herpay for M. gypseum closely resembled those of G. gypseus. OBSERVATIONSCultures of Griffin's isolate of G. gypseus and Szathm~try's isolate of "E. radiosulcatum var. flavum" were obtained and slight differences between their cleistothecia and those of N. incurvata were observed. Single ascospore isolations were made by Miss Christine Dawson, University of Glasgow, and G. ~pseus and the perfect state of "Epidermophyton radiosulcatum var. flavum", like N. incurvata (Stockdale, 1961), were found to be heterothallic.Attempts were then made to cross-mate the three fungi, but without success; cleistothecia were formed only when compatible mating strains from the same parent were mated. All available isolates which had been identified as M. gypseum and did not form cleistothecia by themselves were then mated with the single ascospore isolates. Of the five which had failed to mate with N. incurvata three mated with G. gypseus and two with "E. radiosulcatum var. flavum". None mated with more than one of the single ascospore isolates. 114 at Michigan State University on February 9, 2015 http://sabouraudia.oxfordjournals.org/ Downloaded from THE MICROSPORUM GYPSEUM COMPLEX 1 15Small but constant differences in the cultural and microscopical characters of the imperfect states of the three fungi were also observed, and these were sufficient for isolates subsequently received at th...

Organization and Evolutionary Trajectory of the Mating Type (MAT) Locus in Dermatophyte and Dimorphic Fungal Pathogens

“…Our identification of MAT idiomorphs and meiotic genes (data not shown) in different strains of M. gypseum is the first genomic evidence for sexual reproduction in this dermatophyte species and is well correlated with its known ability to sexually reproduce under laboratory conditions (23,43,50,54). The MAT locus of M. gypseum is similar to those in other Ascomycota: two idiomorphs in which one encodes an alpha domain factor and the other encodes an HMG domain factor, both of which are associated with the APN2, SLA2, and COX13 genes.…”

“…M. gypseum has a defined sexual cycle (50,54), and mating assays were conducted to examine the control of mating type identity by the MAT locus. Cleistothecium formation and production of asci and ascospores (Fig.…”

An Unusual Variant of Microsporum Gypseum (Nannizzia Gypsea)

“…White, fluffy and sterile (so-called "pleomorphic") (Fig 2, "5412 fluffy"). 3. M gypseum typicum, or "wild type," ie, with thin, tan, finely granular, radiating surface growth.…”

“…The inoculation site was covered with gauze and left un¬ disturbed for two weeks, at which time an erythematous, scaly lesion approximately 3 developed. Scrapings showed hyphae and arthrospores in the scales.…”

La classification moderne des dermatophytes

“…Déjà Stockdale [1963] avait démêlé le complexe gypseum et reconnu qu'il était fait de trois espèces parfaites dont d'ailleurs la biologie n'est pas identique. T a k a shio [1973] 2) dans A. benhamiae il faut distinguer deux races qui se distinguent par leur peu de fertilité lorsqu'on les confronte: une race américano-européenne et une race africaine.…”